WATER WORLD Oceans suffering from sea sickness, says study

Seychelles and Germany have the healthiest seas of any inhabited territory, while Sierra Leone has the unhealthiest, according to a new index that says many oceans score poorly for biodiversity and as a human resource.

Topping the list with a score of 86 out of 100 was the uninhabited South Pacific territory of Jarvis Island, owned by the United States, as well as a clutch of other unpopulated Pacific Ocean islands.

The Seychelles, one of only two developing nations in the top 12, ranked fourth with a score of 73 out of 100 -- the same as that of Germany.

The index was devised by researchers in the US and Canada who measured whether the world's oceans are able to provide food and recreation while also sustaining sea life.

They examined the overall condition of 171 exclusive economic zones (EEZs) -- sea areas managed by coastal countries and stretching up to 200 nautical miles into the ocean.

The 171 EEZs represent 40 percent of the world's ocean, but yield the bulk of sea-derived food, recreation and means of livelihood.

Put together, the EEZs scored 60 out of 100, suggesting "substantial room for improvement", said a report in the journal Nature on Wednesday.

"Humans undoubtedly have substantial negative impacts on the ocean, and index scores are negatively correlated with coastal human population," it said.